Extruder Steps/mm Revisited

[dgriff]

Just wondering if anyone has run into this issue before:

When printing with Repetier, I need to have my extruder steps/mm set to 182.640 for it to correctly extrude filament, however when printing on other software (Simplify3D), the extruder steps need to be exactly 1/2 of the Repetier settings (91.32) to achieve the same correct filament extrusion.

Any idea why this is the case? Shouldn't the firmware value be consistent no matter what interface software is being used (ie: the software just says "extrude 1mm" or whatever, and let the printer figure out how many steps to use?)